The research objectives of this project are to contribute to an understanding of the mechanisms by which the pituitary gland develops and matures into a functional endocrine organ. An analysis will be made of the processes of proliferation, growth, differentiation, and functional maturation during normal and abnormal development in two mutants of the mouse which exhibit pituitary dysfunction. The influence of the surrounding mesodermal mesenchyme and of vascularization will also be investigated. A variety of techniques will be used, including histochemistry, autoradiography, electron microscopy, and tissue culture.